Back when picture archiving and communications systems first became a clinical reality, digitizers enjoyed being welcome components in the image management process. Nearly everyone who had a PAC system also had x-rays, as well as the problem of what to do with them.

Digitizers ruled. That is, they did until the rise of computed radiography then digital radiography, which both seemed to signal the twilight of film digitization. But then telerad boomed, validating digitizers once more as necessary image-management appliances.

So now, the wildcard is this: If CR and DR ever take over remote clinics, will digitizers decline again? The makers and users of digitizers say the answer is, well, no. There’s still way too much film, and there will be for a long time.

The journey of image digitizers is a bit of a twister. Take off your shoes, dust off those spinners, and let’s play.

Films R us
“There were people who were building CR systems who speculated that nobody would need a film digitizer anymore,” says Tom Nardozzi, president of Array Corp. USA (Sparta, N.J.), manufacturer of the Array 2905 digitizer. “That was fairly shortsighted thinking. You have people who still produce a ton of film.” Primarily, says Nardozzi, digitizers are used for PACS conversions and telerad applications. One facility that’s using digitizers for both is Inland Imaging in Spokane, Wash.

Spokane has “more facilities than a city its size would normally require, because we do service for a million people outside the Spokane area in small rural communities,” says Jon Copeland, CIO of Inland Imaging. It has five imaging centers and serves 13 hospitals. The network includes 12 digitizers, mostly Array 2905 units. “We have plain film digitizers out in a dozen or so locations [without radiologists on staff] where, if the tech takes a plain film x-ray and wants it read immediately, he or she just digitizes it and sends it across the network. We have a radiologist 24 hours a day, awake, sitting in a room, ready to read these images and call them back with the results.”

In addition, says Copeland, “We’re in the process of converting our entire enterprise to PACS, and we’re taking all of our imaging centers filmless. As a part of that process, we need to get the previous films digital as well. The radiologists don’t want to have to look at the current study on a monitor and have the previous study be on a film, so we’re digitizing the heck out of our old film library. With that included, we’re probably digitizing 30,000 to 50,000 films per year.”

The Alaskan Native Tribal Health Consortium is another good example of how digitizers have been pivotal in implementing PACS and linking farflung health centers. In 1997, the consortium deployed a PACS from eMed Technologies (Lexington, Mass.) to serve its four main facilities: the Alaskan Native Medical Center, the VA Clinic (which serves all U.S. veterans in Alaska), and Elmendorf AFB (the largest Air Force installation in Alaska), all in Anchorage, and Bassett Army Community Hospital in Fort Wainwright, 260 miles north of Anchorage.

Herb Sivitz, the consortium’s director of clinical engineering, says, “For the Indian Health Services side at the Alaskan Native Medical Center, we put a film digitizer and frame grabber in Dillingham, Alaska [350 miles southwest of Anchorage]. We used the Lumisys scanner [now sold by Kodak Health Imaging, Rochester, N.Y.] with the eMed send unit.

“In 1999, a joint partnership-funded project began to put out teleradiology. Phase 2 was to implement in the regional hospitals and clinics that have physicians. There were 11 sites; nine were Indian Health Services, and two were Coast Guard sites. They received digitizers, frame grabbers, and clinical-level reading stations. Then they received bi-directional functionality; they could not only send but they could also pull images back. The main facilities are 150- or 200-bed hospitals. The regional sites range from a 6-bed to 30-bed hospital.” The village sites, says Sivitz, are even smaller. St. Paul Island, for instance, located 1,000 miles from Anchorage in the Bering Sea, has a population of only 600.

Currently there are about 15 digitizers in the consortium’s system. “We’re pretty much putting CR everywhere now, but many of them are keeping the digitizers for doing historicals,” says Sivitz. The two largest facilities digitize a total of about 7,500 images annually, the smaller ones up to 1,000 each.

CAD to the rescue
Another reason digitizers still have a firm grip on healthcare is that, short of a major reimbursement overhaul, they’re mammography’s best chance of becoming a financially viable service. The more automated and accurate mammography becomes, the more tumors it catches early and the more the need for radiologist second reads is reduced, thereby making mammography more economical. This is a major consideration to providers who feel under-reimbursed and understaffed.

Their rescue wagon comes in the form of computer-aided detection (CAD), an image-enhancement technology that relies on digitizers for processing analog mammograms. Recent studies have shown that CAD can improve breast cancer detection by 20 percent, and that it finds more tumors in early stages than radiologists can find without CAD.

R2 Technology (Sunnyvale, Calif.) developed ImageChecker, the first mammo CAD system to gain FDA approval (1998). It uses a CCD digitizer, pattern recognition and artificial intelligence to “spell check” mammograms. After digitizing the mammogram, the image is analyzed by proprietary software that highlights regions of interest (ROIs). Then ImageChecker marks particular ROIs that have physical characteristics associated with microcalcifications or masses. R2 has sold 500 ImageChecker systems.

What about the much-vaunted challenge to digitizers posed by CR and DR? Greatly exaggerated, say vendors.

“CR and DR have really come of age, and so there’s less film being made, but there’s still film,” says Janet Sterritt, director of medical products and programs at Howtek Devices Group (in Hudson, N.H., a division of icad, Inc.). “Most of the PACS installations have CR in them, but mammograms are always going to be on film.” The company is confident that with nearly 10,000 FDA-certified mammography centers in the U.S. and recent increases in reimbursement, the mammography market will eventually reach $1 billion.

Howtek’s current digitizer line, called MultiRad, consists of two products: the 860, used mostly for mammography, and the 460, a favorite of telerad operators. “A couple of years ago,” says Sterritt, “MultiRads were getting used for teleradiology and PACS mostly, and today I see them mostly getting used for CAD. We sell to a great number of CAD vendors.

“CAD is a very different requirement, because you’re shooting an algorithm. If you digitize the same film twice, you have to get the same numbers twice. The specifications have gotten much tighter on the 860 as it’s progressed into the CAD market. There’s no ripple from a fluorescent lamp or a power supply that’s going to cause the film to be any different from one scan to another. It’s tremendously steady. Two or three years ago we might have sold a couple of units a year for CAD, and now it’s really taking over.”

Laser vs. CCD
Nowadays, the bigger question isn’t do we need a digitizer, it’s do we need laser or CCD?

Battling it out for market share are laser digitizers, such as those made by Array and Kodak, and CCD, or charge-coupled device digitizers, like those made by Howtek, Canon USA Medical (Irvine, Calif.) and Vidar Systems Corp. (Herndon, Va.). Laser units were traditionally known for superior image quality. However, newcomer CCD gained a market foothold via lower cost, and now its image quality is catching up to laser’s while its price is not. It’s a rare case where lag is an asset.

“A few years ago, laser was the dominant technology,” says Brian Beardslee, VP and general manager of Vidar, the market leader in CCD digitizer sales. “What happened was, CCDs got better. Vidar started running clinical studies at institutions like Johns Hopkins [Baltimore] and Mallinckrodt [St. Louis]. Clinically, there was no difference” between the quality of the CCD and laser images, nor the CCD and original analog images.

The Johns Hopkins study tested radiologists’ ability to accurately interpret images from a Vidar digitizer compared with film versions of the same images. The Mallinckrodt study showed that 99.7 percent of radiologists tested saw little or no difference in images from Vidar’s economy digitizer compared with one of Kodak’s premium laser digitizers.

“Our least expensive product, our Sierra, has a list price of $10,000,” says Beardslee. “[Mallinckrodt] compared it to Kodak LS 75 [list $26,400], and there was really no difference.”

Except maybe for price, and speed. Laser digitizers may cost twice as much as CCD digitizers, but they scan twice as fast, too.

Kodak’s LS line (formerly Lumiscan) is the technology chosen by a crowd of PACS vendors and distributors that includes eMed Technologies, GE Medical Systems (Waukesha, Wis.), Diagnostic Imaging (Jacksonville, Fla.), Richardson Electronics (LaFox, Ill.), Brit Systems (Dallas), and DR Systems (San Diego). Kodak’s LS 50, LS 75, and LS 85 are designed specially for telerad applications. They are self-calibrating, neatly clobbering the argument favored by CCD proponents that laser digitizers require too much costly scheduled maintenance. In addition, the LS series has patented logarithmic amplifiers that provide, according to the company, better digitizing of grayscale detail at higher densities.

So far, though, that hasn’t been enough to keep CCDs from stealing laser’s turf in radiology. Beardslee says, “From a market share perspective, CCDs have taken over PACS from lasers. When you get down to the nuts and bolts, there’s not a lot of difference, from a radiologist’s perspective, in image quality. But from a value proposition standpoint, there’s a big difference. You can buy a product that has more features for less money.”

Tough to beat
Within the struggle for market domination, all the players agree the action lies not in any whiz-bang technology so much as in the sheer endurance of digitizers, both mechanically and historically.

“They’re not all that exciting,” confides Beardslee. “People want them to be there; they want to be able to have their techs go stick film in them, and to have them work day in and day out and not really have to think about them. It’s like going out to start our cars. We want to stick the key in, turn the engine and it goes.”

The predictability that makes digitizers somewhat boring comes from the same source that makes them desirable, says Rik Primo, division manager of image management at Siemens Medical Solutions (Iselin, N.J.). “The whole secret about digitizing is to make sure the operation of the digitizer is as automated as possible. The moment you have to make manual inputs of, say, patient demographics, you are bound to make important errors.” Some 10 to 20 percent of all manually entered cases have errors, he says, and because Vidar’s digitizers are highly automated and low-maintenance, that’s why Siemens is including the Sierra Plus and DiagnosticPro Plus as standard components in its image management systems.

Other products incorporating Vidar digitizers are the Impax TS 5 transmit/preview station from Agfa HealthCare (Ridgefield Park, N.J.) and the Scanning Workbench digitization station from Brit Systems. Fujifilm Medical Systems USA Inc. (Stamford, Conn.) and Philips Medical Systems (Bothell, Wash.) sell Vidar digitizers with their PACS.

“We try to make them so they basically just run,” says Beardslee about Vidar’s CCD units. “They auto-calibrate. [The distributors’] field service engineers don’t have to do any service” beyond installation. If there’s a problem, they “just hot-swap them out.” In comparison, he says, “the service model for the lasers was pretty complex. You have to have trained people. An operator can’t clear a film jam because the machine eats the film, which results in an on-site service call. That’s why the market changed.”

The whole CCD-versus-laser argument may soon be moot anyway with the imminent arrival of the next generation of film digitizers. Howtek says it received FDA approval in August for a completely new technology designed specifically for CAD applications in early breast cancer detection. It’s neither laser nor CCD-based. What is it, then? At press time, the company would divulge nothing except for that, according to Sterritt, “It’s going to be the product that breaks the mold.” So stay tuned!